Philip Hacker wrote:

However...  This is Ranma 1/2.  You know, there's _gotta_ be a
pressure
point that locks Shimeru into their base gender.  A "cure", so to
speak.

If there is, then why has Dr. Tofu found it or used it for Ranma?

Because Ranma's condition isn't biological.  Pressure points don't
affect magic, except in the way Cologne's did.  The Shimeru
transformation, on the other hand, is a natural function of their
bodies.

I am looking for a way to make "curing" a Shimeru theoretically
possible, but more complicated than simply surgically removing the gland
that produced the hormones that activate the change. Anybody have an
idea?

Getting a secret pressure point technique that "locks" a Shimeru could 
be very complicated indeed.  Consider how much trouble it is to find 
remedies for exotic pressure points like moxibustion or cat's tongue.  
Consider how few would be the number of people who would even be 
interested in learning a technique of such limited general usefulness.